Egg swaps build strong population of California Condors in recovery effort by The Peregrine Fund and partners

7 June 2011

BOISE, Idaho – On a cold spring day in early May, two experts in the effort to save California Condors from extinction met at a highway rest stop in central Oregon, half-way between Boise and Portland. Amid swirling snow and a fierce wind, the two exchanged brief greetings, then quickly transferred precious cargo from one car to the other: a condor egg from the captive flock in Idaho that would be hatched and raised by foster condor parents at the Oregon Zoo.

For Marti Jenkins, head of The Peregrine Fund’s condor propagation program, it was just another day in the effort to produce healthy young condors that eventually will be released to the wild. Egg swaps among the recovery partners are essential to producing a strong population capable of someday sustaining itself without human intervention, Jenkins said.

“By plane, train, or automobile, we try to be sure that these eggs are where they need to be to have the best possible chance at life in the wild,” she said.

A record number of eggs were transferred this year from The Peregrine Fund’s World Center for Birds of Prey to other breeding facilities to bolster the health and productivity of the global population of critically endangered condors. Swaps ensure genetic diversity, help condors establish strong pair bonds, and give biologists an opportunity to swap out an infertile egg with a fertile one in the wild.

““Our pairs in Idaho are so good at producing fertile eggs,” Jenkins said. “They are able to provide support to the entire condor recovery program.”

A total of 18 female condors at the World Center for Birds of Prey laid 19 eggs this season, which began in February. Six of those eggs were transported to the Los Angeles Zoo, one went to the San Diego Zoo Safari Park, and three to the Oregon Zoo. Two eggs produced at the Los Angeles Zoo came to Boise for hatching.

“Condor parents do not distinguish between their own egg and one laid by another pair, so they incubate and raise the swapped eggs as if it were their own,” Jenkins said.

Formerly, the breeding facilities swapped chicks, but the egg swap is easier on everybody, she said.

“By moving the eggs prior to hatch, we are able to distribute the genetics from one facility to another without causing stress to the chick,” Jenkins said. “The chick can then hatch at the facility that is closest to the field site where it will ultimately be released to the wild.”

The final California Condor chick of the season at the World Center for Birds of Prey hatched June 2, the ninth to emerge from its shell since early April. That brings the total number of condors at the World Center for Birds of Prey -- the largest captive flock in the world -- to 66.

The chicks hatched in Idaho will be fed and tended by their parents for about nine months, then join the other young birds in a group aviary for six to seven months. Their final stop is The Peregrine Fund’s release facility at Vermilion Cliffs National Monument in northern Arizona, where they will be released to join the free-flying flock in Arizona and southern Utah.

Separate condor populations are being established by other recovery partners in California and Baja, Mexico. In addition to the Los Angeles, San Diego and Oregon zoos, partners include the U.S. Fish and Wildlife Service, National Park Service, and Ventana Wildlife Society.

“We are fortunate to have such great cooperation with our many partners,” said J. Pete Jenny, president of The Peregrine Fund. “Restoring endangered condors is a huge effort but the result is worth it, knowing that these magnificent birds will be around for future generations to experience and enjoy.”

In the 1980s, the number of condors had dwindled to just 22 birds. Now there are 388 condors, with about half of them flying free in the wild. There are 68 condors in the wild flock in northern Arizona and southern Utah and another nine awaiting release.